Messages in this thread | | | Date | Sat, 27 Mar 2004 20:09:40 -0500 | From | Jeff Garzik <> | Subject | Re: [PATCH] speed up SATA |
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Andrew Morton wrote: > Jeff Garzik <jgarzik@pobox.com> wrote: > >> TCQ-on-write for ATA disks is yummy because you don't really know what >> the heck the ATA disk is writing at the present time. By the time the >> Linux disk scheduler gets around to deciding it has a nicely merged and >> scheduled set of requests, it may be totally wrong for the disk's IO >> scheduler. TCQ gives the disk a lot more power when the disk integrates >> writes into its internal IO scheduling. > > > Slightly beneficial for throughput, disastrous for latency.
If the disk is smart there are surely opportunities for latency optimization as well...
> It appears the only way we'll ever get this gross misdesign fixed is to add > a latency test to winbench.
rotfl ;-) True that...
"IOPs" are what make a lot of storage peeps excited these days, so they are being pushed in a low-latency direction anyway.
Jeff
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